Abstract: A system and method for allowing peers to exchange messages with other peers independently of their network location in a peer-to-peer environment. Messages may be transparently routed, potentially traversing partitions (e.g. firewalls and NATs), and using different protocols to reach the destination peers. In one embodiment, any peer node may serve as a relay peer that allows peers inside a partition to have a presence outside the partition and provides a mechanism for peers outside partitions to discover and communicate with peers inside the partitions. In one embodiment, a relay peer may maintain information on routes to other peers and assist in relaying messages to other peers. In one embodiment, any peer may query a relay peer for route information. In one embodiment, messages may include routing information as part of their payloads.

Abstract: A system and method for providing advertisements in a peer-to-peer networking environment is described. In one embodiment, the peer-to-peer protocols may use advertisements to describe and publish the existence of peer resources. An advertisement may be defined as a structured, language neutral metadata structure that names, describes, and publishes the existence of a peer-to-peer platform resource, such as a peer, a peer group, a pipe, or a service. In one embodiment, user-defined advertisement subtypes (for example, using XML schemas) may be formed from these basic types. A peer in a peer-to-peer network may publish a resource advertisement to make the resource corresponding to the advertisement available to other peers on the network. Peers may discover published advertisements by broadcasting discovery query messages. Other peers may respond to discovery query messages by sending response messages that may include advertisements.